ISOLATION OF TUMOR CELL-SPECIFIC SINGLE-CHAIN FV FROM IMMUNIZED MICE USING PHAGE-ANTIBODY LIBRARIES AND THE RE-CONSTRUCTION OF WHOLE ANTIBODIES FROM THESE ANTIBODY FRAGMENTS

Enhanced expression of epidermal growth factor receptor (EGFR) occurs on a variety of malignant tissues thus making anti-EGFR antibodies pos sible agents for the diagnosis and therapy of human tumors. Standard h ybridoma technology has been used successfully to isolate anti-EGFR an tibodies from immunized mice and rats. This report demonstrates that p hage-antibody libraries are an alternative, and more versatile, method for isolating antibodies from immunized mice. Anti-EGFR antibodies we re isolated from phage-antibody libraries constructed not only from th e spleen of an immunized mouse but also from the draining lymph node o f an immunized mouse and from in vitro immunized mouse cells. Two of t he single-chain Fv isolated from the phage-antibody libraries were eng ineered to create partially humanized whole antibody molecules.